@charset "UTF-8";
article a {
  color: blue;
}

article a:hover {
  color: red;
}

article a {
  color: blue;
}

article a :hover {
  color: red;
}

/*
**在css里边，选择器h1 h2 h3 会同时命中h1元素、h2元素、h3元素。与此类似，.button button会命中button元素和类名
**为.button的元素。这种选择器被称为群组选择器，群组选择器，的规则会对命中群组中任何一个选择器的元素生效。
*/
.button, button {
  margin: 0;
}

.container h1, .container h2, .container h3 {
  margin-bottom: .8em;
}

.container h1, .container h2, .container h3 {
  margin-bottom: .8em;
}

nav a, aside a {
  color: blue;
}

nav a, aside a {
  color: blue;
}

article section {
  margin: 5px;
}

article > section {
  border: 1px solid red;
}

header + p {
  font-size: 1.1em;
}

article ~ article {
  background-color: red;
}

article ~ article {
  background-color: red;
}

article > section {
  background: blue;
}

article dl > dt {
  color: #333;
}

article dl > dd {
  color: #555;
}

nav + article {
  margin-top: 0;
}

article ~ article {
  background: red;
}

article > section {
  background: blue;
}

article dl > dt {
  color: #333;
}

article dl > dd {
  color: #555;
}

nav + article {
  margin-top: 0;
}

nav {
  border-style: solid;
  border-width: 1px;
  border-color: #ccc;
}

nav {
  border: 1px solid #ccc;
  border-left: 0px;
  border-right: 0px;
}
